Question ID - 175084 | SaraNextGen Top Answer
Alkyl halides are insoluble in water but soluble in organic solvents. The insolubility in water is due to their inability to form hydrogen bonds with water. Alkyl bromides and iodides are denser than water whereas alkyl chlorides and fluorides are lighter than water. Alkyl halides have higher boiling points than alkanes of comparable molecular weight. For a given halogen atom, the boiling points of alkyl halides increase with the increase in the size of the alkyl group,

1.Which of the following is liquid at room temperature (b.p. is shown against it)?
(a) $\mathrm{CH}_{3} \mathrm{I}\left(42^{\circ} \mathrm{C}\right)$
(b) $\mathrm{CH}_{3} \operatorname{Br}\left(3^{\circ} \mathrm{C}\right)$
(c) $\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{Cl}\left(12^{\circ} \mathrm{C}\right)$
(d) $\mathrm{CH}_{3} \mathrm{~F}\left(-78^{\circ} \mathrm{C}\right)$
2.Which of the following possesses highest melting point?
(a) Chlorobenzene
(b) $m$-dichlorobenzene
(c) $o$-dichlorobenzene
(d) $p$-dichlorobenzene

3.Read the following statements and choose the correct answer
(i) The builing points of isomeric halualkanes decrease with increase in branching.
(ii) Among isomeric dihalobenzenes the para-isomers have higher melting point than their ortho and metaisomers.
(iii) The isomeric dihalobenzenes have large difference in their boiling and melting points
(iv) The isomeric dihalobenzenes have nearly same boiling point.
(a) (i), (ii) and (iii) are correct
(b) (i) and (iii) are correct
(c) (ii) and (iv) are correct
(d) (i) (ii) and (iv) are correct

4.The decreasing order of boiling points of alkyl halides is
(a) $\mathrm{RF}>\mathrm{RCl}>\mathrm{RBr}>\mathrm{RI}$
(b) $\mathrm{RBr}>\mathrm{RCl}>\mathrm{RI}>\mathrm{RF}$
(c) $\mathrm{RI}>\mathrm{RBr}>\mathrm{RCl}>\mathrm{RF}$
(d) $\mathrm{RCl}>\mathrm{RF}>\mathrm{RI}>\mathrm{RBr}$

a)a,d,d,b b)a,b,d,c c)a,d,d,c d)a,d,d,a

Question

Question ID - 175084 | SaraNextGen Top Answer
Alkyl halides are insoluble in water but soluble in organic solvents. The insolubility in water is due to their inability to form hydrogen bonds with water. Alkyl bromides and iodides are denser than water whereas alkyl chlorides and fluorides are lighter than water. Alkyl halides have higher boiling points than alkanes of comparable molecular weight. For a given halogen atom, the boiling points of alkyl halides increase with the increase in the size of the alkyl group,

1.Which of the following is liquid at room temperature (b.p. is shown against it)?
(a) $\mathrm{CH}_{3} \mathrm{I}\left(42^{\circ} \mathrm{C}\right)$
(b) $\mathrm{CH}_{3} \operatorname{Br}\left(3^{\circ} \mathrm{C}\right)$
(c) $\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{Cl}\left(12^{\circ} \mathrm{C}\right)$
(d) $\mathrm{CH}_{3} \mathrm{~F}\left(-78^{\circ} \mathrm{C}\right)$
2.Which of the following possesses highest melting point?
(a) Chlorobenzene
(b) $m$-dichlorobenzene
(c) $o$-dichlorobenzene
(d) $p$-dichlorobenzene

3.Read the following statements and choose the correct answer
(i) The builing points of isomeric halualkanes decrease with increase in branching.
(ii) Among isomeric dihalobenzenes the para-isomers have higher melting point than their ortho and metaisomers.
(iii) The isomeric dihalobenzenes have large difference in their boiling and melting points
(iv) The isomeric dihalobenzenes have nearly same boiling point.
(a) (i), (ii) and (iii) are correct
(b) (i) and (iii) are correct
(c) (ii) and (iv) are correct
(d) (i) (ii) and (iv) are correct

4.The decreasing order of boiling points of alkyl halides is
(a) $\mathrm{RF}>\mathrm{RCl}>\mathrm{RBr}>\mathrm{RI}$
(b) $\mathrm{RBr}>\mathrm{RCl}>\mathrm{RI}>\mathrm{RF}$
(c) $\mathrm{RI}>\mathrm{RBr}>\mathrm{RCl}>\mathrm{RF}$
(d) $\mathrm{RCl}>\mathrm{RF}>\mathrm{RI}>\mathrm{RBr}$

a)a,d,d,b b)a,b,d,c c)a,d,d,c d)a,d,d,a

Updated On 05-07-2025
By Lithanya Sara

1 Answer

127 votes

By Lithanya Sara · Accepted Answer

Answer Key / Explanation : (c) -

(a) Boiling point of $\mathrm{CH}_{3}$ I is $42^{\circ} \mathrm{C}$ which indicates that it is liquid at room temperature. $\mathrm{CH}_{3} \mathrm{I}$ is larger molecule so it has stronger vander Waal's force of attraction than others.
(d) Para-dichlorobenzene has most symmetrical structure than others. It is found as crystalline lattice form, therefore, it has highest melting point $\left(52^{\circ} \mathrm{C}\right)$ due to symmetrical structure.

(d) (i) (ii) and (iv) arc corrcct.
(c) For the same alkyl group, the boiling points of alkyl halides decrease in the order:
$
\mathrm{RI}>\mathrm{RBr}>\mathrm{RCl}>\mathrm{RF}
$
This is because with the increase in size and mass of halogen atom, the magnitude of van der Waal's forces increases.

Answer Link

DOWNLOAD STUDY MATERIALS FOR
CBSE JEE NEET SAMACHEER

CBSE JEE NEET Test Generator | Online Question Paper Creator & Exam Generator

Answer Link

DOWNLOAD STUDY MATERIALS FOR CBSE JEE NEET SAMACHEER

CBSE JEE NEET Test Generator | Online Question Paper Creator & Exam Generator

DOWNLOAD STUDY MATERIALS FOR
CBSE JEE NEET SAMACHEER